Escalators at Westminster tube station, London

An escalator is a conveyor transport device to transport people, consisting of a staircase whose steps move up or down on tracks which keep the surfaces of the individual steps horizontal. Most escalators also have moving handrails which approximately keep pace with the movement of the steps. The direction of movement (up or down) can be permanently the same, or be controlled by personnel according to the time of day, or automatically be controlled by whomever arrives first, someone at the bottom or at the top (of course the system is programmed such that the direction is not reversed while somebody is on the escalator). In the last two cases there has to be an alternative nearby.

History

Jesse W. Reno invented the first escalator and installed it as an amusement ride at Coney Island, New York in 1897. Charles Seeberger further developed it and joined the Otis Elevator Company, and produced the first commercial escalator which won a first prize at the Paris 1900 Exposition Universelle in France. The German company Orenstein & Koppel (O&K), would also become a major player in escalator design and manufacture.

Design and usage

Escalators in the London Underground used to have wooden steps, but this was changed after the fire at King's Cross St. Pancras tube station in 1987. Old escalators with wooden steps are still in use in some places, however, such as the Tyne Cyclist and Pedestrian Tunnel in Tyne and Wear, England and the Macy's department store in New York City. Modern escalators have metal steps in a continuous loop that move on tracks. Escalators are typically used in pairs with one going up and the other going down. Some modern escalators in stores and shopping malls have glass sides which allow their workings to be viewed. Although most escalators are straight, some shopping malls use curved versions. Most escalators nowadays require people to move on and off in the same direction as the steps are moving. At Earls Court, London, UK, the first escalator installed on the London Underground required people to move on and off from the side of steps at each end of their journey.

When using escalators, passengers who wish to stand and let themselves be carried up or down should stand on one side to allow more impatient users to walk past them. However, which side varies from place to place. On the London Underground and Washington Metro, standers are asked to keep to the right. In the Montreal Metro, there is no rule, as passengers are supposed not to walk on the escalators, a rule scarcely observed and not at all enforced.

There have been reports of people actually falling off a moving escalator or getting their shoe stuck in part of the escalator. At least one person died using an escalator: on February 21 2005, Francisco Portillo, a Salvadorian man living in Boston got his hood stuck in a MBTA escalator and died as a result.

Central-Mid-Levels escalator, Hong Kong

Longest escalators and systems

In Hong Kong, tens of thousands of commuters travel each work day between Central, the central business district, and the Mid-levels, a residential district hundreds of feet uphill, using a long distance system of escalators and moving sidewalks called the Central-Mid-Levels escalator. It is the world's longest outdoor escalator system (not a single escalator span), at a total length of 800m. It goes only one way at a time; the direction reverses depending on rush hour traffic direction. The Ocean Park in Hong Kong also has a long escalator systems connecting two parts of the Park. In the Times Square shopping centre in Causeway Bay there is a bank of four curved escalators, whereby the top of each escalator is approximately facing 180 degrees from the bottom of the same escalator - by necessity the undersides of these escalators are thicker as the step return mechanism needs to be more complex than on a straight escalator.

The longest escalator in the Western Hemisphere is at the Wheaton station of the Washington Metro subway system. It is 230ft (70m) long.

However, the metro systems in several cities in Eastern Europe (including St. Petersburg, Kyiv and Prague) have Soviet-era escalators up to approximately 330ft (100m) long. Those at the Náměstí Míru station in Prague were rebuilt to the same length in 1998–9 by ThyssenKrupp.

Etymology

Escalator was originally a trademark combining the words escalade (an old term for using a ladder to scale a wall) and elevator.